A pro-ferroptotic environment in dystrophic diaphragm is counteracted by GPX4

Duchenne muscular dystrophy (DMD) is a severe muscle-wasting disease caused by the lack of functional dystrophin. We hypothesized that dystrophin deficiency would cause ferroptosis, an iron-dependent cell death pathway, in dystrophin-deficient diaphragms. Given the high frequency of obesity and/or insulin resistance (IR) and glucocorticoid (GC) use in DMD, we further hypothesized that a high-fat, high-sucrose diet (HFHSD) would exacerbate ferroptosis in dystrophin-deficient diaphragm and ferroptosis would be attenuated with GC treatment. To address this hypothesis, C57 and mdx mice were fed a HFHSD or control diet (CD) for 19 w starting at 6 w of age, with subsets receiving prednisolone (Pred; 10mg/L). Glucose and insulin tolerance tests confirmed glucose intolerance and IR in HFHSD-fed C57 and mdx mice. In dystrophin-deficient diaphragms, iron-handling proteins FTH1 (279%, p< 0.01) and transferrin (131%, p< 0.01) were increased in mdx-CD-No Pred (MCN) compared to C57-CD-No Pred (CCN). Likewise, pro-ferroptotic enzymes ACSL4 (36%, p< 0.05) and ALOX5 were elevated (76%, p< 0.01) in MCN compared to CCN. Notably, anti-ferroptotic enzyme GPX4 was increased (728%, p< 0.01), though PRDX6 was decreased (59%, p< 0.01) in MCN compared to CCN. Despite the pro-ferroptotic environment, lipid peroxidation markers MDA and 4HNE were similar between CCN and MCN, even with disease-mediated reductions in catalase, SOD2, and GPX1 (p< 0.01-0.05), suggesting maintenance of redox balance independent of common antioxidant enzymes. The pro-ferroptotic environment of dystrophin-deficient diaphragms was neither improved by Pred treatment nor further antagonized by a HFHSD. In total, dystrophin deficiency induced a pro-ferroptotic intracellular environment in mdx diaphragms, but at this stage of disease, ferroptosis appears to be effectively mitigated by GPX4. This research is supported by MDA grant #962344. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.